RIALTO, Calif. (AP)  Police say a tractor-trailer plowed through the center divider of a Southern California freeway and rammed head-on into traffic. At least four people were killed in the fiery crash.

California Highway Patrol Officer Brian Alvarez says a drilling or cement pumping truck was heading west on Interstate 10 in Rialto when it plowed into oncoming traffic. At least four other cars and trucks were involved in the resulting crash.

TV reports showed the big-rig sprawled on its side near a box truck. Two burned, crushed cars were under the smaller truck.